Timing ruler or timing disk and process for its manufacture

Abstract

The present invention relates to a timing ruler or a timing disk for the exact positioning of working machines, servo-motors, encoders or the like. The device consists of a transparent material on which codings are arranged for scanning via optical sensors. The transparent material consists of a film supporting on one side a light-sensitive layer. The light-sensitive layer is provided via masks or photoplotters with codings for producing windows. The light-sensitive layer is covered with a transparent thermally stable and moisture-resistant material. The invention also relates to a process for the manufacture of such a timing ruler or such a timing disk.

What is claimed is:  
     
       1. A timing device comprising a transparent material on which codings are arranged for scanning via optical sensors, said transparent material consisting of 
       (a) a film;  
       (b) a light-sensitive gelatine layer supported by the film on one-side of said film, said light-sensitive layer being provided with said codings for producing windows; and  
       (c) a transparent, thermally stable and moisture-resistant material covering the light-sensitive layer;  
       wherein the timing device has sealed edges.  
     
     
       2. The timing device according to  claim 1 , further comprising a transmitter located on one side of the timing device and a reflecting layer arranged on the side of the timing device facing away from the transmitter. 
     
     
       3. The timing device according to  claim 2 , wherein the reflecting layer is a metal layer applied by a thin-layer method. 
     
     
       4. The timing device according to  claim 3 , wherein the metal layer consists of copper, aluminum, chromium or silver. 
     
     
       5. The timing device according to  claim 1 , wherein the thermally stable and moisture-resistant material consists of a plastic foil. 
     
     
       6. A process for producing a timing device comprising: 
       (a) providing a film material and a light-sensitive gelatine layer supported on one side of the film material;  
       (b) exposing and subsequently developing the light-sensitive layer to provide codings on the layer for scanning by optical sensors;  
       (c) laminating a foil to the developed layer;  
       (d) cutting the exposed and laminated film material to form an individual timing device body having cut edges; and  
       (e) sealing the cut edges with a hot setting lacquer to form the timing device.  
     
     
       7. The process according to  claim 6 , further comprising providing the exposed and developed film material with a reflecting layer by a thin-layer process. 
     
     
       8. The timing device according to  claim 3 , further comprising a protective layer protecting against physical damage supported on said metal layer. 
     
     
       9. The timing device according to  claim 1  wherein the timing device takes the form of a ring body comprising an outer circumference and an annular bore having a wall, said outer circumference and said wall being covered by a hot setting lacquer. 
     
     
       10. The timing device according to  claim 1  wherein a hot setting lacquer seals the edges of the timing device.